Eric - Great back-of-envelop summary/speculation and I second your desire for someone well-steeped in these modeling/assessment issues.
We (speaking out of school for Merle, Stephen, and the team that went to and met with the Stockholm Team last month) would love to find someone with that depth/breadth of knowledge in this group (or one degree away). I am remiss/slow in following up with the *one* member of the Stockholm Resilience Center I met there who *might* either have this level of depth/breadth or know someone who does. I am trying hard to come up to speed, but the number of models and types of approaches and hidden agendas/constraints/assumptions are still overwhelming. The IPCC seems to be the *best* official source that is most broadly accepted, etc. but tends to be one or two levels of detail above the kinds of questions I have (and you are asking here). I am interested in something much broader than just the geo/bio/cryo/hydro/aero-science of it all, though THAT is huge and complicated enough as it is. The Integrated Assessment Models that join this *physical* domain with the socio(political)economic domain seems most well discussed by the work of the Coupled Model Intercomparison Project (CMIP) lead by LLNL and tied into the World Climate Research Programme (WCRP) who are providing some of the "heavy lifting" for the IPCC's next (VI) report due in 2021. https://en.wikipedia.org/wiki/Coupled_Model_Intercomparison_Project https://www.wcrp-climate.org/ - Steve On 1/19/20 2:00 PM, David Eric Smith wrote: > Would be interesting to know what the buffers are, that weren’t in > that run of models. > > Temperatures are lower than forecast, but Greenland and Antarctic ice > sheet melting rates are higher. They seem like small land areas, and > the ice volume small, but specific heat of melting is large per volume > compared to specific heat of air, and the atmosphere, while thick > compared to ice, is only 10-20 km high (to the top of the troposphere; > stratosphere up to maybe 50km at much-reduced density and much > increased transparency because it is dry). So troposphere maybe 20-40 > times the depth of the west antarctic ice sheet, though only a > lowermost layer of that is melting, and I don’t know the thickness per > unit time lost. Specific heat of dry air is about 1 J/gK, while heat > of melting of clean water is 334 J/g. Ice is about 1000 times as > dense as air, so one has a volume ratio of about 3x10^5 to play with, > per degree Kelvin. > > Greenland plus Antarctica (wikipedia-level area estimates) are about > 3% of earth surface area. So if one divided by a column density ratio > of 30:1 and multiplied by an area ratio of 0.03, one has about 1/1000. > So a full melt of Greenland and Antarctic ice could buffer about 300K > of atmospheric temperature change at a dimensional-analysis-level > estimate. If the full rate of melting were mis-estimated by a factor > that extends the ice sheet lifetimes by 600 years, that would give > about 1/2 degree per year buffering capacity. > > I don’t know what is or isn’t in the models up to 2014, because I > haven’t followed these things closely, but unless what I wrote above > is nonsense, it seems that a mis-estimate of just continental ice > sheet melting is not wildly out of scale to account for unmodeled buffers. > > One also wants to take into account arctic se ice, which if I really > is on a faster melting schedule then some models predicted, though I > don’t have even a good impressionistic memory of what I have heard on > that. > > And of course there is the heat-transport rate of cyclonic storms, > from sea surface to the top of the troposphere, where radiative > transfer through the stratosphere will be much faster than that from > the interior of the troposphere or the surface. My understanding is > that predicting frequency and intensity of typhoons etc. is still > something of a challenge area, but I don’t know if that affects > parameters used in GCM and heat-transfer models enough to count as an > un-modeled buffer. > > Would be great if there is somebody on this list who has a > comprehensive enough knowledge of the state of this literature to give > the kind of survey of the state of the art in response to questions, > that is hard to get from broadcast. Good as it is, broadcast just > contains whatever it contains, and doesn’t have the responsiveness of > a person who can hear a question in context and then recruit knowledge > for a matched reply. > > Eric > > > > > >> On Jan 20, 2020, at 1:55 AM, Pieter Steenekamp >> <piet...@randcontrols.co.za <mailto:piet...@randcontrols.co.za>> wrote: >> >> >> >> Fortunately it seems that the earth is warming much slower than what >> the models predicted. So just maybe we have hope? >> >> >> >> >> >> <image.png> >> >> >> >> _https://judithcurry.com/2015/12/17/climate-models-versus-climate-reality/_ >> >> On Sat, 18 Jan 2020 at 22:36, Jochen Fromm <j...@cas-group.net >> <mailto:j...@cas-group.net>> wrote: >> >> Trump's channel Fox News is owned by the Australian Murdoch >> family. Can two families ruin the entire planet? Trump in America >> and Murdoch in Australia are creating tremendous damage. If >> Climate Change leads to an uninhabitable world, as David >> Wallace-Wells describes in his book, these two families certainly >> contributed to it >> >> https://www.amazon.com/dp/B07GVPFH5V/ref=dp-kindle-redirect?_encoding=UTF8&btkr=1 >> >> >> The Washington Post writes: >> "When we think of industries that must change to prevent further >> global warming, we tend to imagine carbon-intensive concerns such >> as mining, aviation and energy production. But the Murdoch media >> and the rest of the climate denialist industry will also need a >> transition plan. They do not have long to implement it." >> >> https://www.washingtonpost.com/opinions/2020/01/16/australias-catastrophic-fires-are-moment-reckoning-murdochs-media-empire/ >> >> -Jochen >> >> >> ============================================================ >> FRIAM Applied Complexity Group listserv >> Meets Fridays 9a-11:30 at cafe at St. John's College >> to unsubscribe http://redfish.com/mailman/listinfo/friam_redfish.com >> archives back to 2003: http://friam.471366.n2.nabble.com/ >> FRIAM-COMIC http://friam-comic.blogspot.com/ by Dr. Strangelove >> >> ============================================================ >> FRIAM Applied Complexity Group listserv >> Meets Fridays 9a-11:30 at cafe at St. John's College >> to unsubscribe http://redfish.com/mailman/listinfo/friam_redfish.com >> archives back to 2003: http://friam.471366.n2.nabble.com/ >> FRIAM-COMIC http://friam-comic.blogspot.com/ by Dr. Strangelove > > > ============================================================ > FRIAM Applied Complexity Group listserv > Meets Fridays 9a-11:30 at cafe at St. John's College > to unsubscribe http://redfish.com/mailman/listinfo/friam_redfish.com > archives back to 2003: http://friam.471366.n2.nabble.com/ > FRIAM-COMIC http://friam-comic.blogspot.com/ by Dr. Strangelove
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